Grinding-mill



J. STEVENS.

2 Sheets-Sheet; 1.

Grinding Mill.

Patented Aug. 3,1880.

mu-mun I 1$ NPETERS. PROTO-UTHOGRAPHER, WASHKNGTUN. D C.

2 Sheets--Sheet 2 J.- STEVENS.

Grinding Mill. No. 230,834. Patented Aug. 3,1880.

FEE:-

' a t %65Mw I; PEYEIE. F'HOT0-LITHOGRAPNER, WASHlfiGTON. D. C

UNITED STATES PATENT @FFIQE.

Joan s rnvnns, or NEENAH, WISCONSIN.

GRINDING-MILL.

SPECIFICATION forming part of Letters Patent No. 230,834, dated August 3, 1880.

Application filed December 16, 1879.

To all whom it may concern Be it known that I, JOHN STEVENS, of N eenah, in the county of Winnebago and State of Wisconsin, have invented certain new and useful Improvements in Machines for Grinding and Reducing Grain and other Materials, (Case A,) of which the following is a specification.

My invention relates particularly to that class of grinding-mills in which a rotating cylinder works against a stationary breast or concave; and it consists in an improved dress to be givensuch cylinder and concave, and in the various combinations and details of construction hereinafter described and claimed.

In the drawings, Figure 1 is a plan view of the machine. Fig. 2 is a side elevation, with the screws for horizontal adjustment in section. Fig. 3 is a section on the line a; w of Fig. 1; Figs. 4 and 5, modifications of the dress.

The mechanism is mounted upon a strong frame, A, which may be of any approved construction. In blocks a upon this frame are formed bearings for the journals or gudgeons b of the cylinder B, which turns in or against the concave C. This concave is provided with journals at each end, which rest in bearings in the sliding blocks 0, and permit it to be rocked to vary its angle to the periphery of the cylinder.

Extending rearwardly from the concave is an arm or lever, D, through which passes an adjusting-screw, (I, that turns in a swivelblock, (1, journaled in lugs upon the frame, the block being thus journaled or pivoted in order that the screw may accommodate itself to the sweep of the lever as the latter is raised or lowered, and to its endw'lse movements as the concave yields or is adjusted back and forth. Collars or nuts upon the screw confine the lever between them and cause it to rise .and fall as the screw is turned in one direction or the other, thereby controlling the angular adjustment of the concave.

The sliding blocks 0 are held down to the frame by means 0t? bolts or screws which pass through elongated slots in said blocks to permit them to be moved back and forth. A tongue and groove would serve the purpose as well, and might be preferable should the fi'ame be made of iron.

Adjusting-screws E, having their heads at the exterior of the machine, are set into the frame-work or lugs projecting therefrom to the rear of the concave, and determine the maximum limit of distance between the roll and concave-that is, the distance to which the concave may retreat from the roll or cylinder. Coiled springs 0 about these screws give a yieldingpressure to the concave, and the stress of these springs, and consequently the press ure upon the concave, may be adjusted by means of nuts 0 upon the screws, without changing the adjustment of the latter. With this construction alone there would be (langer, when the machinehappened to run empty of feed, of the roll and concave grinding together and destroying the dress. I therefore provide other screws, F, which are threaded into and pass through the pillow-blocks of the concave to and against the pillow-blocks o'fthe roll, and for greater convenience and compactness pass centrally through, without threading into, the screws E, and have their heads or hand-wheels just beyond the heads or hand-wheels of the latter. These determine the minimum of distance between the roll and the concave, but do not restrain the latter from yielding away from the former. They may be threaded into and pass through the pillow-blocks of the roll, and bear against the pillow-blocks of the concave, and perform the same functions, the hand-wheels being made accessible at the exterior of the machine, as before indicated.

It is obvious that the screws E might be omitted, and the springs and means for their adjustment secured to or supported by other provisions, without, however, the advantage of a positive maximum stop. While such a construction is feasible, it would not be as convenient and desirable as the one shown in the drawings.

The adjusting devices above described are capable of general application in machines of this class, and those for horizontal adjustment may readily be applied to roller-mills, or a roller substituted for the concave in the same bearings without aifecting their operation and I therefore do not intend to limit myself to the special application herein illustrated and described.

Above the cylinder and concave it is intended that there shall be placed the hopper and feed-roll commonly found in this class of machines.

The cylinder B is driven in the usual manner, by means of a sheave or pinion mounted upon its shaft 7) and taking power from any suitable prime motor.

To the grinding-surfaces, which may be of any suitable material, as metal or porcelain, I apply a dress consisting of a series of parallel rounded ribs, which, in their preferable form, to take the cylinder for an illustration, upon the advancing side are of easy bevel, butupon the other fall away rapidly. A cross-secticm gives the appearance of a series of saw'teeth, more or less rounded atthe points, and with the re-entrant angles either rounded, blunt, or sharp, the longer sides of these teeth furnishing the active surface.

The ribs in the concave are placed reversely to those upon the roll or cylinder, so that corresponding surfaces of the ribs upon the two face each other and meet as the cylinder revolves.

This dress may differ in fineness for differ ent grades of work, or according to the substance to be reduced, and it may he applied in straight lines, lmlgitudinally of the cylinder, or spirally. It; is adapted for use in roller mills as well as those having concaves, ad visably in such as have one roll geared to run faster than the other.

In the drawings the dress is represented at f. In Fig. 1 it is shown as applied spirally,

being given about a quarter turn in the length ofthc cylinder, although a lesser pitch will be sufficient. The concave may have the dress similarly applied or straight, so that when brought together the ribs of the cylinder will cross those of the concave.

In Fig. 4 I have represented a cylinder with the dress applied in straight lines longitudinally thereof, which mode of application may sometimes be advantageous both in the cylinder and the concave. in this figure, and also in Fig. 5, the dress shown is not the same as that first above described, but is a modification thereof, intended to be substituted therefor either in the cylinder or in the concave, advisably in the former.

At 9 in Fi 4 the ribs are rounded equally on both sides, and the contiguous ribs meet at their bases in a sharp angle, the surface presenting the outline known as invectedj while at h, l ig. 5, there is a well-defined groove between each rib, separating their flanks or bases from each other. "hese ribs will be applied straight or spirally, according as it is desired that they shall coincide with or cross those on the opposing grinding-surface.

The dress made the subject of Letters Patent No. 221,371, granted to me November 4, 1879, consisting of a series of parallel rounded flutes with rounded dividing-ridges, forming a peripheral outline of continuing ogec curves, may also be used upon one grinding-surface in connection with the dress first above described upon the other, the most beneficial effect being obtained by placing the ogee dress upon the cylinder and the beveled dress upon the concave.

As the cylinder throws out wind in its revolution, its grooves may be deeper than those of the concave, which must be limited with reference to the action of this wind.

It is not necessary to the efficient operation of the cylinder and concave provided with my improved dress that. they should be used with the particular adjusting devices shown or be capable of each of the relative adjustments described.

I claim as my invention- 1. A grinding roll. or cylinder having a dress composed of a series of rounded ribs, with the advancing sides of easy bevel and the retreating sides of sharper bevel.

2. A grinding-concave having a dress composed of a series of rounded ribs, with the sides opposed to the revolution of the cylinder of easy bevel and the other sides of sharper bevel.

3. In a grinding-mill, the combination of a cylinder having a dress composed of a series of parallel rounded ribs, with a conca\ 'e having a dress composed of a series of parallel rounded ribs of easy bevel on the sides opposed 'to the revolution of the concave and of sharper bevel on the other sides.

4. In a grinding-mill, the combination of a cylinder having a dress composed of a series of rounded ribs of which the at-h ancing sides are of easy bevel and the retreating-sides of sharper bevel, with a concave having a similar dress applied reverse] y to that upon the cylinder, so that COI'I'OSPOlNllHg faces of the ribs may meet.

5. The concave journaled in sliding blocks, in combination with the rcarwardly-extending lever rigid therewith, and the adjusting-screw working in such lever.

6. The concave journaled in sliding blocks, in combination with the rearwardly-extending lever rigid therewith, and an adjusting-screw working in or against such lever and taking into a swivel-block on the frame.

7. The combi nation, with the concave mounted in sliding blocks, of the adjustingscrews for determining its maximum of retreat from the cylinder and the springs for holding it against such cylinder.

8. The combination, with the concave mounted in sliding blocks, of the adjusting-screws for determining its maximum of retreat from the cylinder, springs for holding it against the cylinder, and means for adjusting the stress of such springs without ali'ecting the adjustment of the screws.

9. The combination, with the concave mounted in sliding blocks, of the adjusting-screws for determining its maximum of retreat from the cylinder, springs for holding it against the cylinder coiled about such adjusting screws, and nuts upon said screws to adjust the stress of the springs.

10. The combination, with the concave moun ted in sliding blocks, of adj ustingscrews having their heads at the exterior of the machine, passing through the frame and threaded into such blocks, and bearing against the pillow-blocks of the cylinder, to determine the minimum of distance between said cylinder and concave.

11. The combination, with the concave mounted in sliding blocks, ot springs to press it against the cylinder aiid adjusting-screws having their heads at the exterior of the machine, passing through the frame and threaded into the pillow-blocks of the concave, and bearing against the pillow-blocks of the cylinder, to determine the limit of approach of said concave to the cylinder.

12. The combination, with the concave mounted in sliding blocks, of springs to press it against the cylinder, adjusting devices to determine its maximum of retreat from said cylinder, and adjusting devices to determine the minimum of distance between the two.

13. The combination of the concave, the adjusting-screws E, to determine its maximum of retreat from the cylinder, and the adjustingscrews F, passing axially through the former, threaded into the sliding block of the concave and bearing against the pillow-block of the cylinder, to determine the minimum of distance between the concave and cylinder.

14. The combination of the concave, the screws E, with their springs and adjustingnuts, and the screws F, passing axiallythrough thefirst-nanied screws.

15. The combination, with the sliding blocks 0, having bearings for the journals of a grinding agent, of the adjusting-screws F, threaded through said block andbearing against the block in which the converse grinderis mounted, to determine the minimum of distance between the two grinding-surfaces.

16. The combination, with the sliding blocks 0, having bearings forthe journals of a grinding agent, of the adjusting-screws E, and the adj usting-screws F, passing axially through the latter, and threaded into and through the sliding blocks, to bearagainst the pillow-blocks of the converse grinder.

17. The combination of the screws for determining the maximum of retreat of the yielding concave. the sliding blocks, the concave journaled therein, the lever extending rearwardly from the concave, and the adj ustingscrew working in the lever and taking into a swivel-block upon the frame.

18. The combination of the screws for determining the maxim um of retreat of the concave, the springs upon such screws, the sliding blocks, the concave journaled therein, the lever extending rearwardly from the concave, and the adjusting-screw working in the lever and taking into a swivel-block upon the frame.

19. The combination of the screws for determiningthemaximum of retreat of the concave,

the screws for determining the minimum of 65 approach of such concave, the sliding blocks, the concave journaled therein, the lever extending rearwardly from the concave, and the adj listing-screw working in the lever and takin into a swivel-block upon the frame.

JOHN STEVENS. \Vitnesses:

J 0s. G. PARKINSON, S. P. HOLLINGSWORTH. 

